Containers with snap-fitting, removable lids often are formed with a mouth defined by a peripheral lip and a channel which together are intended to provide a suitable seal with an associated lid. In most such containers, the lid is applied to the container at the factory to create a satisfactory seal. However, the user often removes the lid with a prying tool, such as a screwdriver, especially if the lid is metal, and this action results in deformation of the container and/or the lid in a manner which may disrupt the formation of a cooperative seal when the lid is later replaced. Such deformation often makes it difficult or impossible to reseal satisfactorily the container utilizing the same lid. As a result, the contents of the container may deteriorate, either hardening or evaporating. Leakage of the contents from the container or leakage of water or other liquids into the container also can occur, either damaging the surface upon which the container is placed or rendering the contents unusable.
A lid which satisfactorily overcomes many of the problems attendant to poor resealing is described in my U.S Pat. No. 4,279,358. The lid described in that patent has an inwardly-facing shoulder formed on its depending sidewall which engages the underside of the protruding lip on the container. That lid is particularly suited for use with certain size and shape container lips, and precise placement of the inwardly-facing shoulder is desirable for optimum seating of the lid.